This invention pertains to a fence useful for a sports field where an athlete can collide with the fence. More specifically, this invention offers a fence that provides containment to a player who runs into the fence. In the present invention, the player comes into contact with a mesh that repels him back onto the field of play with minimum risk of injury. After repelling a player, the safety fence returns to its prior position, thereby maintaining play without disruption.
In many sports, fence-like structures define the perimeter of play. For example, a baseball diamond includes an outfield bounded by a fence (or wall). If a batter hits a baseball beyond the fence, he scores a home run. Accordingly, a baseball player in the outfield may jump up to catch a ball likely to go over the fence.
In these circumstances, the player may collide with the fence, because the player runs toward the fence when he realizes that the ball is sufficiently high for a home run. Injury to the player is likely where the fence is made of rigid materials. The player must therefore balance instantaneously the likelihood of his catching the ball versus the risk of injury if he collides with the fence. Misjudgment leads to either unnecessary reluctance of the player to field a ball or to injury. These problems are more serious for younger, inexperienced players, such as Little League, junior high school, and high school players than for collegiate and professional players.
Attempts have been made to use plastic mesh as fence material in combination with thermoplastic tubes as fence poles. The weight of the fence, however, makes these materials unsuitable. In addition to allowing the fence material to sag, they lack the resilience to restore the fence to its original configuration after it deflects from impact.
In most baseball and softball games played by school teams, the players do not experience the same game as collegiate and professional players do. To hit a home run, the school player has to hit the ball so far that s/he can run all the bases before the ball can be fielded. This situation arises, not from financial limitations (costs of erecting and maintaining fences) but from safety considerations: preventing injury to players. Moving the outfield fence closer to home plate and thus bringing it into play (thereby improving “playability”) is simply too dangerous if the fence is a solid structure, such as plywood/post or chain-link.
Examples from the prior art address safety from both aspects, “playability” and “continuation of play,” without achieving a satisfactory solution.
U.S. Pat. No. 4,284,277 (Aug. 18, 1981) to Leonard et al. for a “Kick Ball Game and Apparatus Kit” discloses a “fabric type mesh net to contain the ball within the playing surface” that “provide[s] a surface off of which the ball may be ricocheted” during the playing of a game of kick ball. This fence cannot contain the impact at full force of a player running at full speed. The “mesh net” boundary fence cannot be adapted to protect players on a baseball or softball field, as the mesh is anchored and is secured directly to the solid support posts. Thus the fence of Leonard et al. presents a significant risk of injury to a player who runs into it.
U.S. Pat. No. 4,605,204 (Aug. 12, 1986) to Schmanski & Landis for a “collapsible recreational fence” discloses a “flexible, resilient, plastic fence mesh attached to fiber reinforced plastic support posts which . . . deflect under the weight of impact.” Though this design is not a solid structure and therefore poses no threat of impact injury, it cannot prevent the player from literally toppling over the fence as it collapses. The player would therefore leave the field. Because the fence of Schmanski & Landis is designed to “immediately restore to an original upright condition”, it cannot satisfy the criterion of “continuation of play”, as can the present invention, because the player would have to climb over the fence to get back into the field of play. Moreover, the height of the fence of Schmanski & Landis makes it possible for a player to jump high enough, while reaching for a ball, to go over the fence backwards, thereby risking a head injury. The pull of the player's legs against the fence may not be sufficient to cause the fence to collapse completely yet be strong enough to cause players to topple onto their heads.
U.S. Pat. No. 5,029,819 (Jul. 9, 1991) to Kane for “Handling and Supporting Flexible Material of a Fence” also discloses mesh material directly attached to rigid support posts, thereby creating a threat of injury if applied to an outfield fence for a baseball or softball field.
U.S. Pat. No. 5,180,143 (Jan. 19, 1993) to Brower discloses a “portable sport boundary fence.” Though not a solid structure, the fence of Brower falls short of keeping the player from injury and ensuring continuation of play. Brower's fence posts “either bend or break to avoid injury to the player.” A broken post is itself a risk to the player who falls on it. Brower's fence is designed to fall away, so a player can fall through the fence, thus ending up outside the field of play. Like the fence of Schmanski & Landis, the height of Brower's fence also poses a hazard if players end up on their heads.
U.S. Pat. No. 6,176,471 (Jan. 23, 2001) to Naegele and Loven for a “Fabric Fence System” also discloses mesh affixed directly to a rigid support structure that includes both vertical and cross members, thereby creating a threat of injury to players.
U.S. Pat. No. 6,851,661 (Feb. 8, 2005) to Penning for a “multi-purpose portable lay-down fence” is also not a solid structure. Penning discloses a framed structure of insufficient height and flexibility. It allows players jumping up for a ball to go over the fence backwards, ending up on their heads outside the field of play. Thus Penning's fence cannot provide both mitigation of the risk of injury and continuation of play.
The verticality of a fall by the player increases the chance of injury because a structure framed or supported by posts offers increased resistance along its vertical plane. The prior art's structures have their maximum flexibility in a horizontal direction. This flexibility diminishes significantly as the vector force of impact increases vertically. Thus a player near the fence who jumps vertically to catch a ball may, because of the fence's short height, fall vertically, thereby challenging the fence's vertical strength. Posts or other framing may cause serious injury to the player by offering significant resistance to a downward force exerted by a falling player.
In addition, none of the structures of the prior art as assembled respond to the effects of high winds.